Electric fuse



G. R. BROWN ELECTRIC FUSE June 7 1927.

Filed June l5, 1924 Inventor: George R BYOu/n,

H is Attorne Patented June; 7, 1927.

] UNITED STATES P GEORGE n. iaRowN, or nnmonronn'oonnncrrcur, assrenon 'ro GENERAL nnndrnrc A oonroaarrron on NEW YORK.

I oomrm,

TEN-T OFFICE.

ELEGTRIC FUSE.

. short circuit, the transformation of the metal of the fuse into fused or gaseous state is'often accompaniediby a heavy explosion.

which disrupts any enclosure or encasement about the'fuse intended to protect persons.

and things from flying particles of molten metal; The larger the fuse the more serious are the consequences ,of its blowing under short circuit action, A

The object of m invention is the provision of an improve electric fuse which shall be adapted, even when of high currentcarrying capacity, to function quietly and without objectionable detonation or explosive action.

It is well known that two or more similar conductors arranged in multiple in an electric CIICllIt'Wlll respectively carry volumes of electric current 1nlnverse proportion to their lengths or resistances, and that the time required to heat a conductor is proportional to the current flowing therein. I make use of these knownfacts in constructing an electric fuse so that its blowing of the several parts thereof will not be simultaneous but in succession to each other.

One embodiment of my invention is shown in perspective in the, accompanying drawing. It consists of a single strip 1 otsheet metal, such as zinc or lead tin alloy, having I Q in its ends the customary slots '2 and 3 by which it is coupled to the binding posts of a-fus'eblock or casing. (not shown) The fuse strip in'its middle or body portion is divided lnto a plurality of conductor bar s.4, 5,6 and 7 of progressively differing lengthsby punching therein narrow longitudinal holes" 8, 9 and 10 of correspondingly different 1. A unitary Application filed June 13, 1924. Serial K0 7115376.

\ By spacing the holes unequally, the widths of the multiple bars are made of unequal widths and as will appear later the longest 1 bar 7 is preferably made narrow or more attenuated than the others.

When such a fuse construction is subjected to ,the passage ofelectric current, the latter will not divide equally between the four bars but in inverse proportion to their respective resistances so that when an abnormal flow takes place the shortest bar 4 disrupts or blows first, then'bars 5, 6 and 7 in seriatim'. Moreover, the final break of the circuit takes place in the longest bar 7 and the are that tends to form confines itself to the volatilization of that bar until the gap produced is too great for the arc to. persist, thus breaking the circuit on an attenuated conductor'with the incident vola-' tilization of only a small percentage of metal that occurs upon the blowing of the .single bar fuses in common use on similar service. 1

By variation in the relative lengths of the bars, or by variation of their relative widths, or by both together, the performance ofmyfl1semay be varied to meet the conditions of any service desired. p

While I have shown and described the best embodiment of the invention knowh to -"me, I do not desire to be restricted thereto.

What I claim as new and desireto secure fuse link comprising a sheet of metal havmg longitudinal apertures of difiering lengths in the body thereof to provide multiple bars of differing conductive capacities. p 1 a 2. A fuse link comprising multiple conductor elements having different conductive capacities, and end members integrall nectin the opposite ends of the elements and a ap'ted to be secured to circuit terminals. i I

In witness whereof, I havehereunto set my hand this eleventh (lay of June, 1924; GEORGE R. BROWN,

by Letters Patent of the United States, 

